1.) A personnel manager has found that historically the scores on aptitude tests given to applicants for entry level positions follow a normal distribution with a standard deviation of 32.4 points. A random sample of 9 test scores from the current group of applicants had a mean score of 187.9. a.) With 80% confidence, what is the sampling error for estimating the population mean score of the current group of applicants? b. ) Did you need to make any assumptions to compute the sampling error in part a? Why or why not? C.) Find an 80% confidence interval for estimating the population mean score of the current group of applicants